Fluorescein
AK-Fluor · Fluorescite
Fluorescent diagnostic dye (yellow-green)
Fluoresces under blue/UV light → visualizes vasculature + perfusion + epithelial defects. Not blue, but grouped with surgical/diagnostic dyes.
Indications
- •Retinal/ophthalmic angiography
- •Corneal epithelial defect detection
- •Perfusion/flap assessment
- •CSF leak identification (intrathecal — off-label, caution)
Dosing
| Context | Adult | Pediatric |
|---|---|---|
| IV angiography | 5 mL of 10% (500 mg) IV | — |
Pharmacokinetics
Onset seconds. Renal excretion → bright yellow urine + transient skin discoloration.
Side effects
- !Nausea/vomiting (common with IV push)
- !Anaphylactoid reactions (rare)
- !Transient yellow skin/urine
- !Intrathecal use → seizures/neurotoxicity (avoid high doses)
Contraindications
- ×Prior fluorescein anaphylaxis
Clinical pearls
- ★Common benign side effect is nausea + transient yellow discoloration; true anaphylaxis is rare but reported.
- ★Does not interfere with pulse oximetry (unlike methylene blue).
Other drugs in Blue Dyes
- Methylene Blue
Inhibits guanylate cyclase + nitric oxide synthase → reverses NO-mediated vasodilation. At low dose, reduces methemoglobin (Fe³⁺) → hemoglobin (Fe²⁺) via NADPH-methemoglobin reductase pathway.
- Isosulfan Blue (lymphatic mapping)
Selectively absorbed into lymphatic capillaries after subdermal/peritumoral injection. Tracks to first-station lymph node → blue staining identifies the sentinel node for biopsy in breast, melanoma, and gynecologic cancers.
- Indocyanine Green (ICG)
After IV or interstitial injection, ICG binds plasma proteins (mostly albumin) and fluoresces at 805–835 nm under near-infrared (NIR) imaging. Used for real-time vascular and lymphatic visualization, hepatic function testing, and tissue perfusion assessment.
- Indigo Carmine
Blue dye rapidly excreted by the kidneys → visualizes ureteral efflux/urine flow. Mild α-agonist activity → transient hypertension.
Browse all classes: /reference/drugs
Suggested reading
- •Miller's Anesthesia, 9e
- •FDA package insert
